This invention relates to a molded, one-piece adaptor for concentrically connecting a steering wheel and a steering wheel shaft. The adaptor has particular utility for connecting a steering wheel shaft having a tubular form, but may be readily modified in order to connect a steering wheel shaft having a rod-like form.
In the past, steering wheels were connected to steering wheel shafts by fitting a rod-like steering wheel column into a larger metallic cylinder and then welding the spokes of the steering wheel to the metallic cylinder.
With the advent of one-piece, molded plastic steering wheels, the spokes of the steering wheel could no longer to welded to the metallic cylinder. Accordingly, a spline mechanism was developed in order to mesh the steering wheel with the adaptor. However, all of these types of adaptors were connected to rod-like steering wheel shafts rather than steering wheel shafts having a tubular form. The connection of the adaptor to the steering wheel shaft was typically made by way of a key in a key way or some type of spline mechanism on the adaptor and the end of the steering wheel shaft. Also, in those types of adaptors, in order to ensure that the steering wheel remained fitted to the steering wheel shaft, a bolt had to be screwed into a hole in the end of the rod-like steering wheel shaft or the end of the steering wheel shaft had to be threaded to screw into the steering wheel.
Recently, there has been a desire to use tubular steering wheel shafts rather than rod-like steering wheel shafts. However, when using tubular steering wheel columns, problems have been encountered with undesirable rocking between the steering wheel and steering wheel shaft. It is believed that this rocking was caused because the fit between the adaptor and steering wheel shaft was not tight enough due to the variations in tolerances in the steering wheel shaft and the adaptor.